Friction stir welding (FSW) tools are refractory alloy or carbide-shouldered cylinders with a central pin or probe, which is rotated at high speed and pressed against the seam of two abutted metal substrates. The frictional heat forms a solid-state weld without melting the base metals.

Dynamic braking resistors (DBRs) produce braking torque and absorb the high amounts of energy generated by stopping electric motors. They are used in variable-speed drive systems such as elevators, cranes, and trains.

...such as magnetic fields and eddy currents. Friction clutches generate friction between contact surfaces. Wrap spring clutches transmit torque from the input to the output through a wrapped spring that uncoils to disengage the clutch. Hydraulic clutches...

...engagement. Noncontact technologies use magnetic fields and eddy currents. Friction torque limiters use the friction between contact surfaces to transmit power. This is the most common configuration. Toothed clutch engagement uses toothed contact...

...are operated through compound linkages. Usually, mechanical actuation is feasible only when the lever or pedal can be located near the clutch. Some mechanical clutches can be actuated from long distances, but friction losses in the linkage or cable may...